DESCRIPTION: (Applicant's Abstract) Drug use by the workforce has the potential to impact significantly on workplace productivity and safety, yet few data are available from studies simulating workplace conditions. Our residential laboratory provides a unique opportunity to investigate drug effects on multiple aspects of human behavior under conditions that closely approximate the environmental context and daily schedule of the workplace. This proposal continues research investigating drug effects on human performance and social behavior, and the relationship between workplace demands and drug-taking behavior. We have demonstrated that the workplace-relevant behaviors under observation (e.g., learning and performance of a variety of work tasks, social behavior, food, tobacco, and caffeine consumption, and participants' verbal reports of drug effects) are differentially sensitive to a variety of pharmacological agents. Three important aspects of these behaviors will be addressed: 1 ) the acute and repeated dose effects of several potentially problematic drugs on behaviors required for workplace productivity and safety; 2) the residual (next day), or "hangover," effects of drug use during non-work time; and 3) workplace performance and drug use following shift change. We will evaluate the effects and likelihood of abuse of smoked marijuana, oral THC (dronabinol), oral methamphetamine, and zolpidem on workplace-relevant behavior. The marijuana-dronabinol studies are timely and important in light of the current changes in marijuana laws in California and Arizona, as well as the sharp increase in marijuana use by the cohort about to enter the workforce. Studying the effects of methamphetamine is particularly relevant given the rapid increase in methamphetamine abuse in the U.S. In addition, we will evaluate the effects of changing work shifts on workplace-relevant behaviors in the presence and absence of drugs that might be used to alleviate the disruptive effects of such shift changes (e.g., sedatives or stimulants). The data collected will be of public health importance, informing both the public and the business communities as well as public policy directed at reducing drug use by the workforce.